An osteoma (plural: "osteomata") is a new piece of
bone
A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, ...
usually growing on another piece of bone, typically the
skull
The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, th ...
. It is a
benign tumor
A benign tumor is a mass of cells ( tumor) that does not invade neighboring tissue or metastasize (spread throughout the body). Compared to malignant (cancerous) tumors, benign tumors generally have a slower growth rate. Benign tumors have r ...
.
When the bone tumor grows on other bone it is known as "homoplastic osteoma"; when it grows on other tissue it is called "heteroplastic osteoma".
Osteoma represents the most common benign
neoplasm
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...
of the nose and
paranasal sinuses
Paranasal sinuses are a group of four paired air-filled spaces that surround the nasal cavity. The maxillary sinuses are located under the eyes; the frontal sinuses are above the eyes; the ethmoidal sinuses are between the eyes and the sph ...
. The cause of osteomata is uncertain, but commonly accepted theories propose embryologic, traumatic, or infectious causes. Osteomata are also found in
Gardner's syndrome
Gardner's syndrome (also known as Gardner syndrome, familial polyposis of the colon, or familial colorectal polyposis) is a subtype of familial adenomatous polyposis (FAP). Gardner syndrome is an autosomal dominant form of polyposis characteriz ...
. Larger craniofacial osteomata may cause facial pain, headache, and infection due to obstructed nasofrontal ducts. Often, craniofacial osteoma presents itself through ocular signs and symptoms (such as
proptosis
Exophthalmos (also called exophthalmus, exophthalmia, proptosis, or exorbitism) is a bulging of the eye anteriorly out of the orbit. Exophthalmos can be either bilateral (as is often seen in Graves' disease) or unilateral (as is often seen i ...
).
Variants
* "
Osteoma cutis, but there is currently no way of detecting if and when this is likely to occur.
* "
Fibro-osteoma"
* "
Chondro-osteoma"
File:Osteom der Stirnhoehle Roentgen.jpg, Osteoma of the frontal sinus seen on x-ray
File:Osteom der Stirnhoehle CT.jpg, Osteoma of the frontal sinus on CT
File:OsteomaMark.png, Osteoma
See also
*
Osteosclerosis
*
Familial adenomatous polyposis
Familial adenomatous polyposis (FAP) is an autosomal dominant inherited condition in which numerous adenomatous polyps form mainly in the epithelium of the large intestine. While these polyps start out benign, malignant transformation into colon ...
*
Exostosis
*
Gardner syndrome
*
Ganglion cyst
A ganglion cyst is a fluid-filled bump associated with a joint or tendon sheath. It most often occurs at the back of the wrist, followed by the front of the wrist. Onset is often over several months, typically with no further symptoms. Occasiona ...
References
External links
* - Osteoid osteoma
* - Osteoma cutis
* Humapt
#4724(Pathology images)
{{Tumors of bone, cartilage, skin, connective, and soft tissue
Osseous and chondromatous neoplasia